Bathtub



FIG. 1 is a front, top, perspective view of a bathtub showing my new design;

FIG. 2 is a front, top, right side perspective view thereof;

FIG. 3 is a rear, top, perspective view thereof;

FIG. 4 is a left side perspective view, the right side being a mirror image thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken line showing is for illustrating purposes only and forms no part of the claimed design. 

The ornamental design for a bathtub, as shown and described. 